In an extraordinary step, a British judge has made public the name of a sperm donor who is said not to have made all the background of his hereditary disease clear to the mothers.

The 37-year-old suffers from the incurable Fragile X symptom, which can lead to learning difficulties but also to cognitive problems.

He had offered himself as a private donor on social networks, as the BBC reported on Tuesday.

High Court Judge Nathalie Lieven decided to lift the anonymity of the man, who is already the father of at least 15 children, to protect other women.

He had shown "fundamental irresponsibility".

The man knew that he was not a candidate for a sperm clinic.

Although he pointed out his illness in his contracts, he did not provide any further explanations.

By his own admission, he believed the disease was not serious and felt that mothers should do their own research.

The case went to court in the city of Derby because the sperm donor requested contact with four of his children.